Butler had a three-run home run in the fourth inning and finished the game needing just a base hit to complete the cycle.
Kansas City won its third in a row and bested Baltimore's Wei-Yin Chen (10-7), who came into the game sporting a 1.95 ERA since the all-star break. Chen lasted 4 2/3 innings Thursday and departed after giving up seven runs on nine hits.
The Royals built a 7-0 lead in the fifth inning when Butler tripled and then scored on a sacrifice fly by Salvador Perez.
Heralded Baltimore rookie Manny Machado made his major league debut at third base Thursday. The 20-year-old went 2-for-4 and scored a run.